1. Field of the Invention
The present invention relates to a flying type thin-film magnetic head with an inductive write head element.
2. Description of the Related Art
Such flying type thin-film magnetic head is in general formed on a magnetic head slider flying above a magnetic disk surface in operation. When a write current flows through a coil of the inductive write head element, Joule heat will be produced and thus an over coat layer or a protection layer for covering the write head element will thermally expand to protrude a part of the magnetic head slider. Therefore, in a recent magnetic head slider with a very low flying height, its rear edge or trailing edge that will have the largest protruded amount may come into contact with and crash onto the surface of the rotating magnetic disk.
In order to prevent such head crash from occurring, the following countermeasures have been proposed:
(1) reduction of heat generation by lowering an electrical resistance of coil in the inductive write head element;
(2) improvement of heat radiation by thinning of an undercoat layer on the substrate;
(3) dissipation of heat by forming a metal pattern on the protection film (Japanese Patent Publication 05-266428-A2);
(4) forming of recess at the trailing edge of the magnetic head slider (Japanese Patent Publication 07-307070-A2); and
(5) forming a recess portion on an air bearing surface (ABS) of the protection layer of the magnetic head slider (Japanese Patent Publication 04-366408-A2).
However, any of the proposed countermeasures cannot sufficiently reduce the protruded amount to satisfy an extremely lower flying height that will be required in future and thus further improvement is required.